Updated Sentry to fix https://github.com/getsentry/sentry/issues/954
Fixed wrong configuration variable name in README
Document SENTRY_URL_PREFIX in README
Replaced config:add commands with config:set
Updated Sentry to v6.3.2
Pull bitbucket credentials from environment variables
Merge pull request #6 from egrim/feature/bitbucket-socialization

Pull bitbucket credentials from environment variables
Update Sentry to v6.4.4
Add Flowdock plugin
Make command in step 4 work with Python 3

Refs #5
Merge remote-tracking branch 'origin/master'

Conflicts:
	requirements.txt
	sentry.conf.py